Dual surveillance camera system

ABSTRACT

A surveillance system having two specialized surveillance cameras with corresponding specialized illuminators is provided in a dual compartment container that eliminates internal light reflection problems by separating each camera and corresponding illuminator while combining each camera with an alternate illuminator, rendering the system more accurate, yet more compact and suited to unobtrusive placement. Considerable heat is generated by the specialized illuminators, requiring a heat sink to preserve illuminator life expectancy and to prevent the adjacent cameras from being adversely affected by the heat. Another feature enabling the system to work in its compact form despite the heat from the illuminators is that the protective case itself is adapted to be a heat sink for the illuminators.

BACKGROUND OF THE INVENTION

This invention relates to security cameras and the obtaining of optimalimages under varying ambient light conditions. In some circumstances, itis most effective to obtain visible light images. In other situations,such as poor visibility due to smoke or fog, infrared images give thebest information about people and objects in the surveillance situation.Versatility and adaptability of the security system to varyingconditions is desired.

With security cameras it is usual to place a protective translucent paneor dome over the camera and illuminator, to guard it against theelements or intentional damage by intruders or others who do not wish tobe observed.

The combination of versatile camera systems with protective cases hasresulted in many such security systems being bulky and difficult toplace in a discreet, unobtrusive way.

SUMMARY OF THE INVENTION

This invention provides a surveillance system having two specializedsurveillance cameras with corresponding specialized illuminators in adual compartment container that eliminates internal light reflectionproblems by an arrangement which concomitantly renders the system morecompact and suited to unobtrusive placement. Considerable heat isgenerated by the specialized illuminators, requiring a heat sink topreserve illuminator life expectancy and to prevent the adjacent camerasfrom being adversely affected by the heat. Another feature enabling thesystem to work in its compact form despite the heat from theilluminators is that the protective case itself is adapted to be a heatsink for the illuminators.

The system achieves its compactness by having a first camera adapted forrecording images under a first type of illumination, a second cameraadapted for recording images under a second type of illumination, afirst illuminator for providing the first type of illumination, a secondilluminator for providing the second type of illumination, and twocompartments, each having a translucent pane. The panes substantiallyface the same way. The first compartment contains the first camera andthe second illuminator. The second compartment contains the secondcamera and the first illuminator. The first and second compartments areseparated from each other by an opaque wall preventing light from thefirst illuminator originating in the second compartment from reflectingoff the second translucent pane directly to the first camera andpreventing light from the second illuminator originating in the firstcompartment from reflecting off the first translucent pane directly tothe second camera.

The first camera records images when the second illuminator is turnedon, the second camera records images when the first illuminator isturned on, and the system switches between using the first illuminatorand the second illuminator, depending on which type of illuminationprovides the best recorded image via its respective camera in ambientconditions for the system from time to time.

In one preferred embodiment, the first camera is a colour camera forobservation under visible light, the second camera is a monochromecamera for observation under infrared illumination, the firstilluminator is a visible light illuminator, and the second illuminatoris an infrared illuminator. The first and second compartments are formedby a box with a dividing wall, the box being formed with cooling fins ofheat-conducting material. These features enable a working, lasting, dualsurveillance camera and dual illuminator system in which thecompartments are small enough resemble a minature speaker cabinet forunobtrusive yet stylish placement. Alternatively the compactness can beused to have a working, lasting, dual surveillance camera and dualilluminator system fit covertly behind an electrical switch box decorcover plate.

The benefits of this dual camera system of imaging are enhanced if thecolour camera has a lens optimized for colour viewing with infra-redfiltering, and the monochrome camera has a lens optimized for monochromeviewing with visible light filtering. The monochrome camera could besupercharged electronically for infrared sensitivity, with the infraredilluminator giving illumination in the range of from 805 to 995nanometers of electromagnetic radiation. Although it is possible for theelectronics of a colour CCTV camera to share a lens with a monochromeCCTV camera, each camera in the present system should have its own lens,and each of the cameras can then have separate varifocal control toenable a switch of mode from day to night operation without a focalshift of the lens, which would otherwise be required when shifting fromcolour to monochrome camera output to obtain the best imaging.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an embodiment of the dual surveillancecamera system of the present invention.

FIG. 2 is a frontal view of the system of FIG. 1.

FIG. 3 is a side view of the system of FIG. 1.

FIG. 4 is a side cross-section of the system of FIG. 1.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, the dual surveillance camera system case 1having in its top compartment a first (colour) camera 2, complete with alens optimized for colour with infra-red filtering, adapted forrecording images under a first type of illumination provided by thefirst (visible light) illuminator 5 in the bottom compartment, andhaving in its bottom compartment a second (monochrome) camera 3,complete with a lens optimized for monochrome viewing with visible lightfiltering, for recording images under a second type of illuminationprovided by the second (infrared) illuminator 4.

A cover 30 secures translucent panes 31 and 32 over the respectivecameras and illuminators, with screws at 24 through 29. The case 1 ismade of heat-conductive material and has integral cooling fins as at 10and 11 to increase surface area contact with surrounding air.

The infrared illuminator 4 and the visible light illuminator 5preferably comprise banks of infrared and visible light emitting diodes(LEDs) respectively. The LEDs give efficient, bright light for theirsize and energy consumption. The LEDs give off considerable heat, whichshould be dissipated by using heat sinks connected to the backboards ofthe LEDs, in order to keep them from overheating and shortening theirpotentially long life span. The cameras themselves can be adverselyaffected if too much heat were allowed to build up in the case 1.

Referring to FIGS. 3 and 4, the first (colour) illuminator 5 in thebottom compartment is powered via wires 18 and 19, while itscorresponding (colour) camera 2 in the top compartment is powered viawires 14 and 15, operating for example a varifocal colour lens control,and the camera's video output signal is sent via wires 16 and 17.Likewise, the second (monochrome) illuminator 4 in the top compartmentis powered via wires 12 and 13, while its corresponding (monochrome)camera 3 in the bottom compartment is powered via wires 20 and 21,operating for example a varifocal mono lens control, and that camera'svideo output signal is sent via wires 22 and 23. The first camera thusrecords images when the second illuminator is turned on, the secondcamera records images when the first illuminator is turned on, and thesystem switches between using the first illuminator and the secondilluminator, depending on which type of illumination provides the bestrecorded image via its respective camera in the ambient conditionsextant for the system from time to time. All the wires are bundled forexit at cable terminal 7, where the system can be connected for remotecontrol and video recording and processing.

The dividing wall 6 is opaque and completely separates the first andsecond compartments, to prevent light from the first illuminator 5originating in the second compartment from reflecting off the secondtranslucent pane 32 directly to the first camera 2 and to prevent lightfrom the second illuminator 4 originating in the first compartment fromreflecting off the first translucent pane 31 directly to the secondcamera 3. It is useful to avoid such premature, internal reflection ofthe illumination because it would be essentially foreground “snow” or“video noise” that would reduce the quality of the imaging from thelight returning from the scene being observed by the respective camera.The system thus provides for higher quality images, optimized as betweenvisible light and infrared light.

The side hole 9 shown in FIG. 1 facilitates mounting of the system witha bracket, in conjunction with the corresponding opposite side hole 8shown in FIG. 3.

The within-described invention may be embodied in other specific formsand with additional options and accessories without departing from thespirit or essential characteristics thereof. The presently disclosedembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalence of theclaims are therefore intended to be embraced therein.

1. A dual surveillance camera system comprising: a) a first cameraadapted for recording images under a first type of illumination; b) asecond camera adapted for recording images under a second type ofillumination; c) a first illuminator for providing the first type ofillumination; d) a second illuminator for providing the second type ofillumination; e) a first compartment having a first translucent viewingpane and containing the first camera and the second illuminator; f) asecond compartment having a second translucent viewing pane andcontaining the second camera and the first illuminator; in which thefirst and second compartments are separated from each other by an opaquewall preventing light from the first illuminator originating in thesecond compartment from reflecting off the second translucent panedirectly to the first camera and preventing light from the secondilluminator originating in the first compartment from reflecting off thefirst translucent pane directly to the second camera.
 2. The dualsurveillance camera system of claim 1, in which the first camera recordsimages when the first illuminator is turned on, the second camerarecords images when the second illuminator is turned on, and the systemswitches between using the first illuminator and the second illuminator,depending on which type of illumination provides the best recorded imagevia its respective camera in ambient conditions fix the system from timeto time.
 3. The dual surveillance camera system of claim 2, in which a)the first camera is a colour camera for observation under visible light;b) the second camera is a monochrome camera for observation underinfrared illumination; c) the first illuminator is a visible lightilluminator; d) the second illuminator is an infrared illuminator; e)the first and second compartments are formed by a box with a dividingwall; f) the box is a heat sink wit cooling fins formed of aheat-conducting material.
 4. The dual surveillance camera system ofclaim 3, in which the compartments are miniaturized to fit withinstandard electrical switch box dimensions in order to be adapted to behidden behind a translucent decor switch plate.
 5. The dual surveillancecamera system of claim 3 in which: a) the colour camera has a lensoptimized for colour viewing, with infra-red filtering; b) themonochrome camera has a lens optimized for monochrome viewing, withvisible light filtering; c) the monochrome camera is supercharged forinfrared sensitivity; d) the infrared illuminator gives illumination inthe range of from 805 to 995 nanometers of electromagnetic radiation; e)the colour camera and the monochrome camera each have an independentlens having a separate varifocal control to enable a switch of mode fromday to night operation without a focal shift.
 6. The dual surveillancecamera system of claim 1, in which: a) the first camera is a colourcamera for observation under visible light; b) the second camera is amonochrome camera for observation under infrared illumination; c) thefirst illuminator is a visible light illuminator; d) the secondilluminator is an infrared illuminator.
 7. The dual surveillance camerasystem of claim 6, in which the colour camera has a lens optimized forcolour viewing, with infra-red filtering.
 8. The dual surveillancecamera system of claim 6, in which the monochrome camera has a lensoptimized for monochrome viewing, with visible light filtering.
 9. Thedual surveillance camera system of claim 6, in which the monochromecamera is supercharged electronically for infrared sensitivity.
 10. Thedual surveillance camera system of claim 6, in which the infraredilluminator gives illumination in the range of from 805 to 995nanometers of electromagnetic radiation.
 11. The dual surveillancecamera system of claim 6, in which the colour camera and the monochromecamera each have an independent lens having a separate varifocal controlto enable a switch of mode from day to night operation without a focalshift.
 12. The dual surveillance camera system of claim 1, in which thefirst and second compartments are formed by a box with a dividing wall.13. The dual surveillance camera system of claim 12, in which thecompartments are miniaturized to fit within standard electrical switchbox dimensions in order to be adapted to be hidden behind a translucentdecor switch plate.
 14. The dual surveillance camera system of claim 1,in which the first and second compartments have cooling fins formed of aheat-conducting material.
 15. The dual surveillance camera system ofclaim 1, in which the first and second compartments are contained in abox that is a heat sink.